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    聚苯基荧光酮修饰玻碳电极吸附溶出伏安法测定痕量汞

    Adsorption Stripping Voltammetric Determination of Trace Amounts of Mercury with Polyphenylfluorone Modified Glassy Carbon Electrode

    • 摘要: 研究利用聚苯基荧光酮修饰玻碳电极测定痕量汞的溶出伏安法,在0.1 mol·L-1氨水-NH4Cl缓冲溶液中(pH 9.5),开路搅拌,Hg(Ⅱ)富集于修饰电极表面,通过介质交换至0.1 mol·L-1盐酸溶液中,于-0.40 V还原后阳极化线性扫描,在0 V左右处获得一灵敏汞的溶出峰.其氧化峰电流与Hg(Ⅱ)浓度在9.0×10-8~8.0×10-7mol·L-1范围内呈线性关系,开路富集5 min,检出限达2.0×10-8mol·L-1.应用此方法于尿液中汞的测定,所得平均RSD值小于4.02%,回收率试验结果在98.4%~103.2%间.

       

      Abstract: A polyphenylfluorone modified glassy carbon electrode (PPF-GCE) was prepared by electropolymerization,and used in the adsorption stripping voltammetric determination of traces of mercury.In a 0.1 mol·L-1 ammoniacal buffer solution of pH 9.5,and under the condition of open circuit,Hg(Ⅱ) ion was accumulated (in 5 min) on the surface of the modified electrode by forming a complex with phenylfluorone.After changing the medium from ammoniacal solution to 0.1 mol·L-1 HCl solution,in which Hg(Ⅱ) was reduced at -0.40 V,and anodic potential scanning was carried out starting from -0.4 V in the positive direction a sensitive peak of mercury due to anodic stripping was observed around 0 V.Values of oxidative peak current of mercury was found to keep linear relationship with its concentration in the range of 9.0×10-8-8.0×10-7mol·L-1,with its detection limit of 2.0×10-8mol·L-1.The proposed method has been applied to the determination of mercury in urine samples,giving average value of RSD′s less than 4.02%,and values of recovery in the range from 98.4% to 103.2%.

       

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